If you can't use TLS 1.0 anymore Updated January 25, 2018 16:21 Description If you can't use TLS 1.0 anymore using a commerce site and you get errors like this for instance: “Could not establish trust relationship for the SSL/TLS" Resolution Add the following in an initialization module or under Application_Start(): ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;